Foot manifolds, apparatuses, systems, and methods for applying reduced pressure to a tissue site on a foot

ABSTRACT

Apparatuses, systems, and methods for applying reduced pressure to a tissue site on a foot are provided. An apparatus may include an insole and a tissue contacting surface covering at least a portion of the insole. At least one portion of the tissue contacting surface is removable to form a void. The apparatus may also include a reduced-pressure interface for receiving reduced pressure from a reduced-pressure source, and at least one flow channel fluidly coupled to the reduced-pressure interface and the void.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/655,210, filed Oct. 18, 2012, which is a continuation of U.S. patentapplication Ser. No. 12/404,111, filed Mar. 13, 2009, which applicationclaims the benefit of U.S. Provisional Application No. 61/036,433 filedMar. 13, 2008, which is hereby incorporated by reference.

BACKGROUND

The illustrative embodiments relate generally to medical treatmentsystems and, more particularly, to foot manifolds, apparatuses, systems,and methods for applying reduced pressure to a tissue site on a foot.

Clinical studies and practice have shown that providing a reducedpressure in proximity to a tissue site augments and accelerates thegrowth of new tissue at the tissue site. The applications of thisphenomenon are numerous, but application of reduced pressure has beenparticularly successful in treating wounds. This treatment (frequentlyreferred to in the medical community as “negative pressure woundtherapy,” “reduced pressure therapy,” or “vacuum therapy”) provides anumber of benefits, which may include faster healing and increasedformulation of granulation tissue.

SUMMARY

According to an illustrative embodiment, an apparatus for applyingreduced pressure to a tissue site on a foot includes an insole and atissue contacting surface covering at least a portion of the insole. Atleast one portion of the tissue contacting surface is removable to forma void. The apparatus may also include a reduced-pressure interface forreceiving reduced pressure from a reduced-pressure source, and at leastone flow channel fluidly coupled to the reduced-pressure interface andthe void.

In one illustrative embodiment, a system may include, in addition to theapparatus described above, a reduced-pressure source operable to supplyreduced pressure. The system may also include a delivery conduitoperable to deliver reduced pressure from the reduced-pressure source tothe reduced-pressure interface of the apparatus.

In one illustrative embodiment, a method for applying reduced pressureto a tissue site on a foot includes providing a foot manifold andremoving a portion of a tissue contacting surface that covers an insoleof the foot manifold to form a void. The method also includes aligningthe void with the tissue site on the foot and creating a substantiallypneumatic seal between the void and the tissue site. The method alsoincludes applying reduced pressure from a reduced-pressure source to thevoid via a flow channel such that reduced pressure is applied to thetissue site.

In one illustrative embodiment, a method of manufacturing an apparatusfor applying reduced pressure to a tissue site on a foot includesproviding an insole and providing a tissue contacting surface. Themethod also includes covering at least a portion of the insole with thetissue contacting surface to form at least one flow channel operable totransfer reduced pressure.

Other objects, features, and advantages of the illustrative embodimentswill become apparent with reference to the drawings and detaileddescription that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a system for applying reducedpressure to a tissue site on a foot according to an illustrativeembodiment;

FIG. 2 illustrates a perspective view of an apparatus for applyingreduced pressure to a tissue site on a foot according to an illustrativeembodiment;

FIG. 3A illustrates a cross-sectional view of the apparatus of FIG. 2;

FIG. 3B illustrates a cross-sectional view of the apparatus of FIG. 2,the apparatus having a support member removed to form a void;

FIG. 4A illustrates a top perspective view of a support member of theapparatus of FIG. 2;

FIG. 4B illustrates a bottom perspective view of the support member ofFIG. 4A;

FIG. 5 illustrates an exploded perspective view of an apparatus forapplying reduced pressure to a tissue site on a foot according to anillustrative embodiment;

FIG. 6 illustrates a perspective view of the apparatus of FIG. 5 with aportion of a sealing layer removed to form a void;

FIG. 7 illustrates a cross-sectional view of a delivery conduitaccording to an illustrative embodiment;

FIG. 8 illustrates a cross-sectional view of a delivery conduitaccording to an illustrative embodiment;

FIG. 9 illustrates a top view of an apparatus for applying reducedpressure to a tissue site on a foot according to an illustrativeembodiment; and

FIG. 10 illustrates a perspective view of the apparatus of FIG. 9applied to a tissue site on a foot according to an illustrativeembodiment.

DETAILED DESCRIPTION

In the following detailed description of the illustrative embodiments,reference is made to the accompanying drawings that form a part hereof.These embodiments are described in sufficient detail to enable thoseskilled in the art to practice the invention, and it is understood thatother embodiments may be utilized and that logical structural,mechanical, electrical, and chemical changes may be made withoutdeparting from the spirit or scope of the invention. To avoid detail notnecessary to enable those skilled in the art to practice the embodimentsdescribed herein, the description may omit certain information known tothose skilled in the art. The following detailed description is,therefore, not to be taken in a limiting sense, and the scope of theillustrative embodiments are defined only by the appended claims.

Referring to FIG. 1, an illustrative embodiment of a reduced-pressuretreatment system 100 for providing reduced-pressure treatment to atissue site 102, such as a wound 104, on a foot 105 of a patient ispresented. The reduced-pressure treatment system 100 includes a footmanifold 106 that receives reduced pressure from a reduced-pressuresource 109, and which supplies reduced pressure to a tissue site on thefoot 105. The foot manifold 106 includes an insole 108, and a tissuecontacting surface 110 that covers the tissue facing surface of theinsole 108. As used herein, “covers” includes fully or partiallycovering. The reduced pressure may be delivered to the foot manifold 106through a delivery conduit 112, which may be inserted, or otherwiseremovably coupled, to a reduced-pressure interface 114 located at therear 116 of the insole 108. A portion of the tissue contacting surface110 is removable to form a void 118, which may be aligned with the wound104 when the foot manifold 106 and foot 105 are adjacent. One or moreflow channels 120 in the insole 108 transfers reduced pressure from thereduced-pressure interface 114 to the void 118 such thatreduced-pressure treatment is delivered to the wound 104.

As used herein, “reduced pressure” generally refers to a pressure lessthan the ambient pressure at a tissue site that is being subjected totreatment. In most cases, this reduced pressure will be less than theatmospheric pressure at which the patient is located. Alternatively, thereduced pressure may be less than a hydrostatic pressure at the tissuesite. In one embodiment, the reduced pressure may initially generatefluid flow in the delivery conduit 112 and proximate the wound 104. Asthe hydrostatic pressure around the wound 104 approaches the desiredreduced pressure, the flow may subside, and the reduced pressure may bemaintained. Unless otherwise indicated, values of pressure stated hereinare gauge pressures. The reduced pressure delivered may be static ordynamic (patterned or random) and may be delivered continuously orintermittently. Although the terms “vacuum” and “negative pressure” maybe used to describe the pressure applied to the tissue site, the actualpressure applied to the tissue site may be more than the pressurenormally associated with a complete vacuum. Consistent with the useherein, an increase in reduced pressure or vacuum pressure typicallyrefers to a relative reduction in absolute pressure. Unless otherwiseindicated, as used herein, “or” does not require mutual exclusivity.

The wound 104 may be any type of wound, or damaged area of tissue, andmay include wounds from trauma, surgery, or other causes, such as adiabetic ulcer. The tissue site 102, which includes the wound 104, maybe the bodily tissue of any human, animal, or other organism, includingbone tissue, adipose tissue, muscle tissue, dermal tissue, vasculartissue, connective tissue, cartilage, tendons, ligaments, or any othertissue. Treatment of the tissue site 102 may include removal of fluids,e.g., exudate, or delivery of reduced pressure.

In the example in which the wound 104 is a foot ulcer, the insole 108may also serve to off-load pressure from the wound 104, such as when thepatient is walking or standing. The tissue contacting surface 110 maymaintain contact with the tissue around the wound 104, thereby relievingpressure from the wound 104. The pressure exerted upon the wound 104 isreduced due to the presence of the void 118 adjacent the wound 104. Inparticular, because the portion of the tissue contacting surface 110that is adjacent the wound 104 is removed, the pressure exerted upon thewound 104 is reduced.

The foot manifold 106 may be used in conjunction with or in lieu oftherapeutic casting systems, such as total contact casting and removablecast walkers. For example, the foot manifold 106 may be placed into atherapeutic casting system that is worn by the patient. In anotherexample, the foot manifold 106 may be inserted into any article offootwear, such as a shoe, boot, sandal, or sock.

The foot manifold 106 may also be secured to the foot 105 in other ways.For example, a securing member 122 may be at least partially wrappedaround the insole 108 and the foot 105. Adhesive may be used to preventthe securing member 122 from unwrapping. If desired, the foot 105 andthe foot manifold 106 that have been wrapped by the securing member 122may be placed in footwear, including a therapeutic casting system. Thefoot manifold 106 may also be secured to the foot 105 using one or moreelastic bands that press the foot manifold 106 and foot 105 against oneanother.

In another example, the foot manifold 106 may adhere to the foot 105without the need for the securing member 122 or footwear. In thisexample, the tissue contacting surface 110 of the foot manifold 106 maybe made from or coated with an adhesive material that secures the foot105 to the foot manifold 106.

A foam manifold 124 may be inserted into the void 118. The foam manifold124 assists in applying reduced pressure to, delivering fluids to, orremoving fluids from the wound 104. The foam manifold 124 typicallyincludes a plurality of flow channels or pathways that areinterconnected to improve distribution of fluids provided to and removedfrom the wound 104 adjacent the foam manifold 124. The foam manifold 124may be a biocompatible material that is capable of being placed incontact with the wound 104 and distributing reduced pressure to thewound 104. Examples of foam manifolds 124 may include, for example,without limitation, devices that have structural elements arranged toform flow channels, such as, for example, cellular foam, open-cell foam,porous tissue collections, liquids, gels, and foams that include, orcure to include, flow channels. The foam manifold 124 may be porous andmay be made from foam, gauze, felted mat, or any other material suitedto a particular biological application. In one embodiment, the foammanifold 124 is a porous foam and includes a plurality of interconnectedcells or pores that act as flow channels. The porous foam may be apolyurethane, open-cell, reticulated foam, such as a GranuFoam® materialmanufactured by Kinetic Concepts, Incorporated of San Antonio, Tex. Insome situations, the foam manifold 124 may also be used to distributefluids, such as medications, antibacterials, growth factors, and varioussolutions to the wound 104. Other layers may be included in or on thefoam manifold 124, such as absorptive materials, wicking materials,hydrophobic materials, and hydrophilic materials.

Reduced pressure is delivered to the void 118 through the flow channel120. Although the foot manifold 106 is shown to have only a single flowchannel 120, the foot manifold 106 may have any number of flow channels,such as flow channel 120, that are able to fluidly connect any portionof the insole 108 or tissue contacting surface 110 with thereduced-pressure interface 114. As described in the figures below, theseflow channels may be interconnected, form any pattern, or defined by oneor more grooves on the insole 108 or the tissue contacting surface 110.The flow channel 120 may also be a tube or conduit that fluidly couplesthe reduced-pressure interface 114 to the void 118.

Reduced pressure is delivered to the flow channel 120 via thereduced-pressure interface 114. The reduced-pressure interface 114 maybe any socket, port, hole, or other attachment capable of facilitatecoupling, including the fluid coupling, between the delivery conduit 112and the foot manifold 106. As used herein, the term “coupled” includescoupling via a separate object and includes direct coupling. The term“coupled” also encompasses two or more components that are continuouswith one another by virtue of each of the components being formed fromthe same piece of material. Also, the term “coupled” may includechemical, such as via a chemical bond, mechanical, thermal, orelectrical coupling. Fluid coupling means that fluid is in communicationbetween the designated parts or locations.

In one non-limiting example, the reduced-pressure interface 114 mayinclude a hole into which the delivery conduit 112 may be inserted,thereby forming an interference fit. Upon insertion of the deliveryconduit 112 into the reduced-pressure interface 114, reduced pressuremay be delivered to the flow channel 120 and the void 118 from thereduced-pressure source 109. A mechanism may also be used to secure thedelivery conduit 112 to the reduced-pressure interface 114 to preventthe delivery conduit 112 from being pulled out of the reduced-pressureinterface 114. In one embodiment, the delivery conduit 112 is integrallyformed with the reduced-pressure interface 114 such that the deliveryconduit 112 is fixedly coupled to the reduced-pressure interface 114.The reduced-pressure interface 114 may also include a swivel, hinge, orother movable attachment mechanism to permit the delivery conduit 112 tomove or swivel relative to the insole 108.

The delivery conduit 112 may include one or more lumens through which afluid may flow. In one embodiment, the delivery conduit 112 includes twoor more lumens, any of which may be used to transfer reduced pressure tothe foot manifold 106, transfer liquid, such as exudate, away from thefoot manifold 106, or transfer therapeutic fluids to the foot manifold106.

The reduced-pressure source 109 provides reduced pressure to the footmanifold 106. The reduced-pressure source 109 may be any means ofsupplying a reduced pressure, such a vacuum pump. While the amount andnature of reduced pressure applied to a site will typically varyaccording to the application, the reduced pressure will typically bebetween −5 mm Hg and −500 mm Hg.

A medial portion 125 of the delivery conduit 112 may have one or moredevices, such as device 126. For example, the device 126 might beanother fluid reservoir, or collection member to hold exudates and otherfluids removed. Other examples of the device 126 that might be includedon the medial portion 125 of the delivery conduit 112 or otherwisefluidly coupled to the delivery conduit 112 include the followingnon-limiting examples: a pressure-feedback device, a volume detectionsystem, a blood detection system, an infection detection system, a flowmonitoring system, a temperature monitoring system, etc. Some of thesedevices may be formed integral to the reduce-pressure source 109. Forexample, a reduced-pressure port 128 on the reduced-pressure source 109may include a filter member that includes one or more filters, e.g., anodor filter.

In use, a patient or caretaker may remove a portion of the tissuecontacting surface 110 to form the void 118. The portion of the tissuecontacting surface 110 that is removed is detachably mated to the insole108, and may be chosen such that the void 118 aligns, or is otherwiseadjacent, the wound 104 when the foot manifold 106 and the foot 105 areadjacent one another. Grid lines or markers may be included on thetissue contacting surface 110 to assist in choosing the appropriateportion of the tissue contacting surface 110 for removal. The foammanifold 124 may be inserted into the void 118. When in use, the foot105 and the foot manifold 106 are disposed adjacent one another tocreate a substantially pneumatic seal between the void 118 and the wound104. As described below, the substantially pneumatic seal may befacilitated in variety of ways, including through the use of a sealingmember (not shown) or the tissue contacting layer 110 itself. Reducedpressure may then be applied to the foot manifold 106 from thereduced-pressure source 109. The reduced pressure may be transferredthrough the delivery conduit 112 and into the void 118 via thereduced-pressure interface 114 and the flow channel 120, therebyproviding reduced-pressure treatment to the wound 104. The substantiallypneumatic seal formed at the wound 104 helps to maintain the reducedpressure at therapeutic levels.

Referring to FIGS. 2, 3A-B, and 4A-B, an illustrative embodiment of thefoot manifold 206 includes the insole 208. The foot manifold 206 alsoincludes support members 232, which are functionally analogous to thetissue contacting surface 110 in FIG. 1.

In one embodiment, the insole 208 is shaped and sized to approximate theplantar region 230 of the foot 205, but may also cover only a portion ofthe plantar region 230, such as the heel region. The insole 208 may alsocover all or a portion of the dorsal region, toes, sides, or rear of thefoot 205. The insole 208 includes a ridge 252, which may help to securethe foot 205 to the foot manifold 206 and prevent movement of the insole208 relative to the foot 205 or the wound 204. In another example, theinsole 208 does not have the ridge 252.

The insole 208 may be formed from any material. For example, the insole208 may be composed of a flexible or elastic material, such as silicon,polyurethane, or a thermoplastic elastomer. The flexible or elasticcomposition of the insole 208 may also facilitate the insertion of theinsole 208 into an article of footwear.

The support members 232 form a layer that covers a tissue facing surface234 of the insole 208. The support members 232 contact the plantarregion 230 of the foot 205, and may provide an off-loading function thatcan reduce the pressure exerted on the wound 204. Although shown ashexagonal, the support members 232 may have any shape, including,without limitation, a square, rectangle, triangle, octagon, polygon,circle, oval, or irregular shape.

The flow channels 220 are disposed between the support members 232 andthe insole 208, and are formed by a tissue facing surface 254 of theinsole 208 and the grooves 236 on the insole-facing side 237 of thesupport members 232. The grooves 236 may be formed along three axes 238,239, 240. Each side 242 of the support member 232 may include a groove236. However, some support members 232, such as those support members onthe periphery 244 of the layer formed by the support members 232, mayhave sides 242 that do not include a groove 236. When the supportmembers 232 cover the insole 208, the grooves 236 form an interconnectednetwork of flow channels 220 that distributes reduced pressure along theinterface 245 between the support members 232 and the insole 208. Thesupport members 232 comes into contact with the insole 208, or may becoupled to the insole 208 using any known technique, including withoutlimitation welding (e.g., ultrasonic or RF welding), bonding, adhesives,cements, etc. In one embodiment, the support members 232 are coupled tothe insole 208 to seal the flow channels 220 and keep reduced pressurefrom leaking out of the flow channels 220 leading to the void 218.

In one embodiment, the grooves 236 are arch-shaped grooves. However, thegrooves 236 may have any shape. For example, the grooves 236 may haveone or more straight side walls such that, when the support member 232is coupled to the insole 208, an at least partially polygonal flowchannel is formed.

The support members 232 may include one or more insertion slots 246. Theinsertion slots 246 may be adapted to receive a device that facilitatesthe removal of each of the support members 232, such as a scalpel. Theinsertion slots 246 may have any shape, and the shape may depend uponthe type of device to be used in the removal of the support members 232.

The support members 232 at the periphery 244 include lap joints 248. Inone example, the lap joints 248 are included only on those supportmembers 232 on the periphery 244 of the layer formed by the supportmembers 232. The lap joints 248 facilitate a sealed connection betweenthe support members 232 and the insole 208. Although the lap joints 248are shown to be polygonal protrusions, the lap joints 248 may also berounded protrusions or any other protrusion that can facilitate a sealedconnection between the support members 232 and the insole 208.

The support members 232 may also be made of any material capable ofsupporting the foot 205. For example, each of the support members 232may be made of elastic, flexible, or soft materials. The elasticqualities of the support members 232 may lessen the pressure exertedupon the tissue site. Non-limiting examples of the material from whichthe support members 232 may be composed include silicon (including soft,conformable silicon), polyurethane, and a thermoplastic elastomer (TPE).

Any one or more of the support members 232 may be removed to form thevoid 218. In FIG. 2, support members 232 a are removed to form the void218. The support members 232 a may be chosen based on their location onthe insole 208 such that the wound 204 is adjacent the void 218 when thefoot 205 is placed adjacent the foot manifold 206. Markers, such ascharacters, may be included on the support members 232 to help locatethe support members 232 a that align with the wound 204. A sealingmember 250 may be disposed around the void 218 and between the foot 205and the support members 232 when the foot 205 is applied to the footmanifold 206. The foot 205 may be positioned on the sealing ring 250 andthe support members 232 such that a seal is formed at the void 218. Theseal that is formed by the sealing member 250 helps to prevent theescape of reduced pressure from the void 218 such that a therapeuticreduced pressure may be maintained at the void 218 and applied to thewound 204.

The sealing member 250 may have any shape and may be made of anymaterial that helps to form a seal at the void 218. For example, thesealing member 250 may be a hydrogel ring. The sealing member 250 mayalso be formed from putty, silicon, closed cell polymer foam, TPE, or asoft, flexible, elastic, or adhesive material.

Upon removing the support members 232 a, the void 218 may be fully orpartially filled with the foam manifold 224. Before placement into thevoid 218, the foam manifold 224 may be smaller, larger, or approximatelyequal in volume to the void 218. The shape of the foam manifold 224 mayalso be any predetermined shape, or customized to fit the void 218.Also, the foam manifold 224, once inserted into the void 218, may expandto fill the void 218, and may press against the insole 208 or thesupport members 232 adjacent the void 218

In one embodiment, the foam manifold 224 may be torn or cut from a foamsheet. The foam sheet may also be pre-cut to include foam manifold 224that approximate the size of the void 218, or the size of the supportmember 232. In an alternate embodiment, the foam manifold 224 may beplaced into or on the wound 204 prior to applying the foot 205 to thefoot manifold 206. In another embodiment, no foam manifold 224 need beused when treating the wound 204 with reduced pressure.

The foam manifold 224 in the void 218 may have a height 256 thatapproximates the height of the support members 232. The foam manifold224 may also have a height 258 that is greater than the height of thesupport members 232, and which may touch the wound 204. In anotherembodiment, the foam manifold 224 is shorter than the height 256 of thesupport member 232.

In FIG. 3B, support member 232 c, which is disposed between supportmembers 232 b and 232 d in FIG. 3A, has been removed to form the void218. Reduced pressure that is applied to the foot manifold 206 passesthrough the interconnected flow channels 220 formed by the grooves 236and the tissue facing surface 254 of the insole 208 to reach the void218. As explained above, the sealing member 250 may be used to create aseal at the void 218 such that a therapeutic reduced pressure ismaintained at the void 218 and applied to the wound 204. In theillustrative embodiments, reduced pressure may be applied only to thoseportions of the foot 205 at which reduced-pressure treatment is desired,while supporting the remainder of the foot 205 using the support members232.

Referring to FIGS. 5 and 6, a foot manifold 506 that includes a sealinglayer 510 is shown according to an illustrative embodiment. The sealinglayer 510 is functionally analogous to the tissue contacting layer 110in FIG. 1. The sealing layer 510 is bonded, or otherwise coupled, to theinsole 508, and covers all or a portion of the insole 508.

The insole 508 includes a flow channels 520, which are interconnectedand formed by grooves 536 and protrusions 560 in the insole 508. Theflow channels 520 form a grid. However, the flow channels 520 may formany pattern, including irregular patterns or no pattern at all. The flowchannels 520 are further defined by an insole-contacting side of thesealing layer 510 when the sealing layer 510 abuts the insole 508.Reduced pressure may be provided to the flow channels 520 via thedelivery conduit 512.

The sealing layer 510 may be composed of any material. For example, thesealing layer 510 may be composed of a flexible material that is capableof providing a sealed connection between the sealing layer 510 and theinsole 508. In one non-limiting example, the sealing layer 510 may be ahydrogel layer. The tissue-facing side 562 or the insole-facing side ofthe sealing layer 510 may be adhesive. Adherence between thetissue-facing side 562 of the sealing layer 510 and the foot 105 mayhelp to secure the foot 105 to the foot manifold 506.

A portion 532 may be identified, cut, and removed from the sealing layer510 to form the void 518. The portion 532 may be removed using anydevice capable of cutting the sealing layer 510, such as a scalpel. Afoam manifold may be inserted into the void 518. A foot may be disposedon top of the sealing layer 510 such that a tissue site, such as awound, on the foot abuts the void 518. Reduced pressure may betransferred to the flow channels 520 via the delivery conduit 512, andthe reduced pressure may be transferred through the flow channels 520 tothe void 518.

The sealing characteristics of the sealing layer 510 help to preventreduced pressure that is transferred to the void 518 from escaping,thereby maintaining a therapeutic reduced pressure for the tissue siteabutting the void 518. The sealing layer 510 may thus eliminate the needfor a sealing member. Using the sealing layer 510, the void 518 may belocated anywhere on the sealing layer 510, and the portion 532 of thesealing layer 510 that is removed to form the void 518 may have anyshape. The location and shape of the removed portion 532 may bedetermined based on a location and shape of a wound on a foot, such as afoot ulcer. Grid markers, such as grid lines, may be printed, orotherwise included, on the sealing layer 510 to help identify theportion of the sealing layer 510 that should be removed to align thevoid 518 with a wound on a foot. The grid markers may also help todetermine the healing progress of the wound as the sealing layer 510 isreplaced during overall treatment of the wound.

Referring to FIG. 7, a delivery conduit 712 that is functionallyanalogous to the delivery conduit 112 in FIG. 1 is shown according to anillustrative embodiment. The delivery conduit 712 has an elongated shapehaving a low profile. The elongated shape of the delivery conduit 712alleviates the pressure points applied to the portions of the foot,ankle, or leg that are adjacent the delivery conduit 712. The deliveryconduit 712 may also have other shapes, such as a circular, elliptical,polygonal, or curved “U” shape.

The delivery conduit 712 may also be made of any material, such as aflexible, elastic, or compressible material. The flexible, elastic, orcompressible material may alleviate the pressure points applied toadjacent portions of the foot, ankle, or leg. Non-limiting examples ofmaterial from which the delivery conduit 712 may be formed includeplastic, nylon, silicon, polyurethane, TPE, or PVC.

The delivery conduit 712 includes two lumens 766, 768. In one example,the lumens 766, 768 transfer reduced pressure to one or more flowchannels in a foot manifold. The delivery conduit 712 may have anynumber of lumens, including three or more lumens. In addition, one ormore of the lumens in the delivery conduit 712 may be used to transportfluid, such as liquid or exudate, from a wound to a fluid collectionapparatus. In other embodiments, the lumens 766, 768 may have any shape,such as a circular, elliptical, or polygonal shape.

The lumen 766 is bound by a first wall 770 and a second wall 771.Similarly, the lumen 768 is bound by a first wall 772 and a second wall773. The first walls 770, 772 include protrusions 774, 775,respectively. The protrusion 774 prevents the first wall 770 fromtouching the second wall 771 when a force is applied to the deliveryconduit 712 in a direction indicated by arrows 776. The protrusion 775prevents the first wall 772 from touching the second wall 773 when aforce is applied to the delivery conduit 712 in a direction indicated byarrows 776. In this manner, the protrusions 774, 775 help prevent thelumens 766, 768 from collapsing.

The second walls 771, 773 include protrusions 777, 778, respectively.The protrusion 774 touches protrusion 777 when a force is applied to thedelivery conduit 712 in a direction indicated by arrows 776 such thatthe portion of the first wall 770 and the second wall 771 that do nothave protrusions 774 and 777 do not touch one another. Similarly, theprotrusion 775 touches protrusion 778 when a force is applied to thedelivery conduit 712 in a direction indicated by arrows 776 such thatthe portion of the first wall 772 and the second wall 773 that do nothave protrusions 775 and 778 do not touch one another. The lumens 766,768 may be prevented from collapsing in this manner.

Referring to FIG. 8, the delivery conduit 812 includes an angled divider880, which separates lumens 866, 868 from one another. The angleddivider 880 may alleviate pressure points on a foot, ankle, or leg whenthe foot, ankle, or leg presses against the delivery conduit 812 in adirection indicated by arrow 876. In this example, the angled divider880 may flatten when the foot, ankle, or leg presses against thedelivery conduit 812 in a direction indicated by arrow 876. The angleddivider 880 may form an approximately 45 degree angle with the wall 873of the lumen 868, or any other lumen wall in the delivery conduit 812.

Referring to FIGS. 9 and 10, an insole 908 is shown according to anillustrative embodiment. The insole 908 may be placed on a dorsal region982 of the foot 905, and, in particular, at the toe region of the foot905. In one example, the insole 908 may be composed of a foam, such asreticulated foam or a GranuFoam® material. The insole 908 may be coupledto the toe region of the foot 905 via the securing member 922. Reducedpressure may be applied to the toe region by the insole 908 usingreduced pressure that is delivered from a reduced-pressure source anddelivered via the delivery conduit 912.

The insole 908 includes protrusions 984, which may be inserted betweenthe toes of the foot 905. The insole 908 may also include voids 918through which reduced pressure may be applied to a region between thetoes of the foot 905. In another non-limiting example, each of theprotrusions 984 may be placed on an individual toe of the foot 905. Theprotrusions 984 may have any shape that facilitates the application ofreduced pressure to the desired portion of the toe region of the foot905.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative, non-limiting embodiments, it shouldbe understood that various changes, substitutions, permutations, andalterations can be made without departing from the scope of theinvention as defined by the appended claims. It will be appreciated thatany feature that is described in a connection to any one embodiment mayalso be applicable to any other embodiment.

What is claimed is:
 1. An apparatus for applying reduced pressure to atissue site on a foot, the apparatus comprising; an insole having aplurality of protrusions extending from at least a portion of the insoleto form a surface with grooves located between the protrusions; asealing layer covering the surface of the plurality of protrusions andforming flow channels with the grooves, a portion of the sealing layeradapted to have an opening to form a void configured to be in fluidcommunication with the tissue site, wherein at least a portion of theflow channels are fluidly coupled to the void for providing a reducedpressure to the void; and a reduced-pressure interface fluidly coupledto the flow channels and adapted to receive reduced pressure from areduced-pressure source for providing reduced-pressure to the void andthe tissue site.
 2. The apparatus of claim 1, wherein the opening in thesealing layer exposes at least a portion of two protrusions and thegroove between the protrusions to form the void.
 3. The apparatus ofclaim 1, wherein the at least one flow channel contains a tubetransferring reduced pressure from the reduced-pressure interface to thevoid.
 4. The apparatus of claim 1, further comprising: a sealing memberoperable to substantially seal the void, the sealing member adapted tobe disposed between the surface of the plurality of protrusions and thetissue site.
 5. The apparatus of claim 1, wherein the at least one flowchannel is at least partially formed by a groove on the insole.
 6. Theapparatus of claim 5, wherein the grooves forms a grid pattern.
 7. Theapparatus of claim 1, further comprising: a foam manifold disposed inthe void and adapted to further distribute reduced pressure to thetissue site.
 8. The apparatus of claim 1, further comprising: a deliveryconduit fluidly coupled to the reduced-pressure interface and operableto transfer reduced pressure from the reduced pressure source to thereduced-pressure interface.
 9. The apparatus of claim 8, wherein thedelivery conduit comprises at least two lumens operable to transfer thereduced pressure from the reduced pressure source to thereduced-pressure interface, and wherein at least one wall of the atleast two lumens has a protrusion operable to prevent the lumen fromcollapsing.
 10. The apparatus of claim 1, further comprising: a securingmember operable to secure the insole adjacent the tissue site.
 11. Theapparatus of claim 1, wherein the void is adjacent the tissue site, andwherein the reduced pressure in applied to the tissue site via the void.